It is known from the state of the art to enable a content provider to deliver content to a mobile terminal via a communication network. The content provider produces and provides a content, e.g. a video clip with BBC news. The actual delivery of the content is then usually taken care of by a service provider, e.g. a network operator, who delivers the content provided by the content provider to the terminal.
It is also known to enable a “push” delivery of content, i.e. a delivery initiated by the content provider not by a request of a user of a mobile terminal.
In a provider initiated delivery of a content, a content clip can be delivered to a mobile terminal more or less automatically as soon as the clip becomes available, e.g. as part of a multimedia message. The delivery can be organized in a way that it does not require any user actions like clicking on a corresponding uniform resource locator (URL) for retrieving the content clip. An automatic delivery of content clips has to be supported by the mobile terminal to which it is directed. Further, it typically requires that the user of the mobile terminal has subscribed beforehand to a service providing these content clips. It is possible to enable a user to order a content directly from the respective content provider or via a service provider.
The communication network which is made use of for delivering the content may comprise different types of radio access networks for enabling an access of mobile terminals. Such different types of radio access networks provided by a single communication network can be e.g. a 3G (3rd generation) radio access network and a 2G (2nd generation) radio access network, or within a 3G system an UTRAN (universal mobile telecommunication services terrestrial radio access network) employing WCDMA (wideband code division multiple access) and a GSM (global system for mobile communications) radio access network.
Further, mobile terminals have been proposed that are able to access a communication network via different types of radio access networks and thus via different radio access technologies (RAT). Such mobile terminals are referred to as multi-mode terminals. One example for a multi-mode terminal is a 2G/3G dual-mode terminal.
In order to enable a comprehensive use of such multi-mode mobile terminals, it has also been proposed that a communication network providing different radio access technologies should support an intersystem handover of a multi-mode mobile terminal between these technologies.
The network signaling employed for performing an intersystem handover between UMTS (universal mobile telecommunication services) and GSM is described for example in the technical specification 3GPP TS 23.060 V3.6.0 (2001-01): “General Packet Radio Service (GPRS); Service description; Stage 2 (Release 1999)”.
There are several reasons for which a change of the radio access technology is enabled.
The most important reason for an intersystem handover is differences of coverage and quality in the communication system. In some situations, the coverage of a first radio access system to which a moving mobile terminal is currently connected may end. Moreover, the radio connection quality provided by this first radio access system may degrade below a given threshold value. If at the same time, another radio access system still provides coverage and/or a better radio connection quality, an intersystem handover can guarantee a continued and satisfactory supply of the mobile terminal. The first radio access system is typically a WCDMA system and the second radio access system a GSM/GPRS system.
Another essential reason for an intersystem handover is load, i.e. the current amount of traffic in different radio access systems. When the load in a first radio access system exceeds a pre-defined threshold value, an overflow of mobile terminals can be handed over to another radio access system. In this case, the first radio access system is typically GSM/GPRS and the second radio access system WCDMA.
A third reason for an intersystem handover is QoS (quality of service) requirements of requested services. The operator of the communication system defines service based handover criteria according to its preferences. These criteria are then stored in a service priority table in the core network, which initiates the handover. The same table resides additionally in the radio network controller (RNC) of an UTRAN of the communication system. The table in the RNC can be used in case the RNC receives no handover information from the core network. In an exemplary assignment of services to different radio access technologies, GSM may be preferred for speech and WCDMA for packet data, while circuit data has to be transmitted using WCDMA. An additional criterion for a service based handover is load, load and service based handover thus being a more accurate term than service based handover.
As specified for example in the technical specification 3GPP TS 25.413 V3.4.0 (2000-12): “UTRAN Iu Interface RANAP Signaling (Release 1999)”, a service based handover from a 3G UTRAN to a 2G GSM radio access network is implemented by an optional parameter called “Service Handover” in the RANAP (radio access network application part) messages “RAB Assignment Request” and “Relocation Request” on the Iu interface between the core network and an UTRAN. Three values are defined for this parameter, “HO to GSM should be performed”, “HO to GSM should not be performed” and “HO to GSM shall not be performed”. Thus, the core network is not able to force the RNC to carry out a handover from a 3G to a 2G radio access network, but only to propose a handover. The final decision is taken by the RNC based on additional criteria like load, coverage and radio connection quality. Furthermore, in load and service based handovers, an RNC hands mobile terminals over to a base station subsystem (BSS) periodically and in groups, not immediately and on an individual basis.
A problem that may result in the delivery of content to a multi-mode mobile terminal and that cannot be solved with the currently known methods relates to licensing. In the media world, it is a common approach to provide a license for distributing a specific content only through a certain access, e.g. for TV and radio broadcasting via cable, via a terrestrial access, i.e. analog, digital, AM, FM, HF, UHF, and/or VHF, or via satellite systems. In mobile communications, in contrast, content licenses are rather new. Still, some content providers have already sold exclusive licenses to mobile communication network operators and to other service providers for providing a certain content on a limited radio access spectrum, e.g. GSM and UMTS bands or technologies. An operator typically has both, 2G and 3G networks, and is able to provide a lot of content via 3G radio access to 3G/2G dual-mode terminal users. However, if this operator has only a 2G license for a certain content, a technical solution to provide the licensed content to its dual-mode subscribers on the 2G band would be useful. When the dual-mode mobile terminal of the dual-mode subscriber tries to access the 2G-only content via the 3G radio access network, it must be moved to the 2G system in order to enable the access. After content delivery by means of download, streaming or MMS (multimedia messaging service) via 2G radio access network, the terminal can either be moved to the 3G system or stay in the 2G system.
Further, a situation may arise in which a content is to be delivered which requires a specific radio access technology. A 2G/3G mobile terminal, for example may operate either in a 3G WCDMA system or in a 2G GSM system. The WCDMA system is then regularly the preferred system. GSM, however, has some services which do not exist in 3G, for example transparent facsimile.
The current 3GPP specifications treat UTRAN, GSM and GERAN radio access cells equally, i.e. there are no strong means for the network operator to guide a mobile terminal towards the most suitable radio access technology. It is known to favor one or another public land mobile network (PLMN), location area (LA), routing area (RA) or cell based on defined criteria. However, cells of different radio access technologies may be mixed in a single PLMN, LA or RA, and no method has been proposed so far for forcing the mobile terminal to a specific radio access technology, and not even for favoring a certain radio access technology. Only if a requested service cannot be provided in the current serving cell, the call may be handed over to another cell by the network, or the call may be cleared.
The European patent application EP 1 162 805 A1 describes a delivery of content upon a request of a user, in particular a request via a mobile terminal. It is proposed that due to the high costs, only a reduced content is delivered to the mobile terminal, while the full content is provided to an alternate system, in particular a wired system. Providing the full content to this alternate system can be realized e.g. by means of a “push” delivery to an internet connected data processing system. The document does not deal, however, with the requirement of delivering content to a mobile terminal via a specific type of radio access network in a “push” delivery.